U.S. Pat. No. 8,074,742 issued to Scott et al. discloses a reaming tool for use during emplacement of tubular strings such as casing or liner in wellbores drilled through subsurface formations.
A rotary power section described in the above referenced patent may include a turbine section operated by flow of drilling or other fluid through an interior of the wellbore tubular being emplaced so that a reaming head can rotate without rotation of the wellbore tubular. It has been observed that fluid pressure used to operate the rotary power section may place large axial loading on bearings included in the power section to support such loading. It is desirable to have a reaming tool power section for use in emplacement of wellbore tubular that has more balanced axial loading resulting from fluid pressure.